Biotope: Found in Lake Hyanuary and the sorrounding slow flowing rivers near the Brazilian city of Manaus.

Social behavior: A peaceful, active schooling fish, that can be kept with similar sized Characins or other small fishes in a community tank.

Diet: Omnivorous; They eat small invertebrates in nature, but will accept all kinds of live, frozen and good quality dried foods in the aquarium.

Breeding: Quite easy

Tank: Minimum 60 litres

Population: 6-7 fish for 70 litres

Decoration: They can be kept in a densely planted tank, or in a biotope setup. In a biotope tank use sandy bottom with some dried leaves, that stain the water. Decorate the aquarium with driftwood and roots. They are sensitive to water quality, so regular water changes are essential. Use dim lighting.

Temperature: 23-27 °C

pH: 6-7.5

Hardness: 0-15 NK°

Lifespan: 3-5 years

Description: January Tetra’s back is olive green while its belly is silvery. An iridescent yellowish-green stripe runs from the gill cover to the caudal peduncle, and also a black band runs below this stripe, from the tail to the middle of the body. The fins are transparent or pale yellow. There is a dark spot with golden border at the base of the caudal fin. The common name Green Neon is very confusing as this fish is not closely related to the Neon Tetra (Paracheirodon innesi). Despite its colors Hemigrammus hyanuary is seen less often in the hobby than it used to be.

Males are slimmer and slightly smaller than females and they have a small hook on their anal fin which is not always easy to see. They should be bred in a separate aquarium that contain a few clumps of fine-leaved plants and has very dim lighting. January Tetra will deposit the eggs among the plants. Alternatively the base of the aquarium can be covered with a mesh with large enough grade, so that the eggs can fall through it, which will protect the eggs from the parents. The water in the breeding tank should be very soft (1-5 gH) and slightly acidic (pH 5.5-6.5) with a temperature of around 26-28 °C. The use of reverse osmosis water is also possible that can be filtered through peat to achieve the desired effect. They can be bred in pairs or in small groups, but before breeding, feed the fish with plenty of live foods. Transfer the adult fish to the spawning tank in the evening and they will usually spawn on the following morning. The number of the eggs can vary between 100 and 200. Once the eggs are noticed in the aquarium, the adult fish should be removed, as they will eat the eggs. The eggs hatch in 24-36 hours, and the fry become free swimming after 3-4 days. Because of their small size, the fry can be fed with infusoria-type food or liquid food. The eggs and fry are light sensitive in the early stages of life and the tank should be kept in darkness. The iris of their eyes become bright green when they reach sexual maturity.